Epenthesis

Epenthesis is a phonological process in which an extra sound is inserted into a word. The inserted segment is usually a vowel, but consonants can also be added in some languages. The purpose is to facilitate pronunciation, to break up difficult consonant clusters, or to resolve hiatus between adjacent syllables. Epenthesis can be phonemic, forming part of the language’s distinct sound system, or allophonic, occurring as a predictable variant in certain phonetic contexts. It is a common mechanism in shaping syllable structure and in loanword adaptation.

Two common manifestations are vowel epenthesis and consonantal epenthesis. Vowel epenthesis inserts a vowel to create a permissible syllable structure, often to avoid illegal clusters or to ease transitions between morphemes. Consonantal epenthesis inserts a consonant to break up a cluster or to align with the language’s phonotactics. Epenthetic segments may be obligatory in a language or optional in particular phonological environments; in connected speech, epenthesis may also occur across word boundaries.

Examples illustrate its cross-linguistic reach. In Japanese, loanwords are frequently adapted with epenthetic vowels to fit a CV syllable system, as in sutoraiku for strike and konpyuutaa for computer. In other languages, epenthesis can occur to ease the pronunciation of foreign clusters or within rapid speech, yielding pronunciations such as a schwa inserted between consonants. Epenthesis is distinct from related processes like metathesis and assimilation, though it can interact with them and influence overall phonological patterns.

Etymology and further reading can be traced to the Greek term epentesis, meaning “placing upon.”